|
Tucson Amateur Packet Radio
TAPR is an international amateur radio organization. It was founded in Tucson, Arizona, in 1981 by a group of amateurs interested in developing a terminal node controller (TNC) for amateur use. Thus, the group was named Tucson Amateur Packet Radio, Inc. After developing one of the first widely available TNCs, TAPR rapidly became a national and then international group. It now identifies itself simply by the acronym TAPR rather than the spelled-out name. TAPR no longer has any direct connection with Tucson, Arizona. Today, TAPR no longer focuses on packet radio, but continues as a research and development oriented group offering kits, assembled products, and publications related to the intersection of amateur radio and digital technology. TAPR describes itself as "A community that provides leadership and resources to radio amateurs for the purpose of advancing the radio art." Current products and development activity relate to software-defined radio, GPS, APRS and time an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Radio
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications. The term "amateur" is used to specify "a duly authorised person interested in radioelectric practice with a purely personal aim and without pecuniary interest;" (either direct monetary or other similar reward) and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.). The amateur radio service (''amateur service'' and '' amateur-satellite service'') is established by the International Telecommunication Union (ITU) through the Radio Regulations. National governments regulate technical and operational characteristics of transmissions and issue individual station licenses with a unique identifying call sign, which mus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal Node Controller
A terminal node controller (TNC) is a device used by amateur radio operators to participate in AX.25 packet radio networks. It is similar in function to the Packet Assembler/Disassemblers used on X.25 networks, with the addition of a modem to convert baseband digital signals to audio tones. The first TNC, the VADCG board, was originally developed by Doug Lockhart, VE7APU, of Vancouver, British Columbia. Amateur Radio TNCs were first developed in 1978 in Canada by the Montreal Amateur Radio Club and the Vancouver Area Digital Communications group. These never gained much popularity because only a bare printed circuit board was made available and builders had to gather up a large number of components. In 1983, the Tucson Amateur Packet Radio (TAPR) association produced complete kits for their TNC-1 design. This was later available as the Heathkit HD-4040. A few years later, the improved TNC-2 became available, and it was licensed to commercial manufacturers such as MFJ. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tucson
, "(at the) base of the black ill , nicknames = "The Old Pueblo", "Optics Valley", "America's biggest small town" , image_map = , mapsize = 260px , map_caption = Interactive map outlining Tucson , image_map1 = File:Pima County Incorporated and Unincorporated areas Tucson highlighted.svg , mapsize1 = 250px , map_caption1 = Location within Pima County , pushpin_label = Tucson , pushpin_map = USA Arizona#USA , pushpin_map_caption = Location within Arizona##Location within the United States , subdivision_type = Country , subdivision_type1 = State , subdivision_type2 = County , subdivision_name = United States , subdivision_name1 = Arizona , subdivision_name2 = Pima , established_title = Founded , established_date = August 20, 1775 , established_title1 = Incorporated , e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Four Corners region with Utah to the north, Colorado to the northeast, and New Mexico to the east; its other neighboring states are Nevada to the northwest, California to the west and the Mexican states of Sonora and Baja California to the south and southwest. Arizona is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912. Historically part of the territory of in New Spain, it became part of independent Mexico in 1821. After being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase. Southern Arizona is known for its desert cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software-defined Radio
Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in analog hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which were once only theoretically possible. A basic SDR system may consist of a personal computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the general-purpose processor, rather than being done in special-purpose hardware (electronic circuits). Such a design produces a radio which can receive and transmit widely different radio protocols (sometimes referred to as waveforms) based solely on the software used. Software radios have signif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Packet Reporting System
Automatic Packet Reporting System (APRS) is an amateur radio-based system for real time digital communications of information of immediate value in the local area. Data can include object Global Positioning System (GPS) coordinates, weather station telemetry, text messages, announcements, queries, and other telemetry. APRS data can be displayed on a map, which can show stations, objects, tracks of moving objects, weather stations, search and rescue data, and direction finding data. APRS data is typically transmitted on a single shared frequency (depending on country) to be repeated locally by area relay stations (digipeaters) for widespread local consumption. In addition, all such data are typically ingested into the APRS Internet System (APRS-IS) via an Internet-connected receiver (IGate) and distributed globally for ubiquitous and immediate access. Data shared via radio or Internet are collected by all users and can be combined with external map data to build a shared live v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Counter
A frequency counter is an electronic instrument, or component of one, that is used for measuring frequency. Frequency counters usually measure the number of cycles of oscillation, or pulses per second in a periodic electronic signal. Such an instrument is sometimes referred to as a cymometer, particularly one of Chinese manufacture. Operating principle Most frequency counters work by using a counter which accumulates the number of events occurring within a specific period of time. After a preset period known as the ''gate time'' (1 second, for example), the value in the counter is transferred to a display and the counter is reset to zero. If the event being measured repeats itself with sufficient stability and the frequency is considerably lower than that of the clock oscillator being used, the resolution of the measurement can be greatly improved by measuring the time required for an entire number of cycles, rather than counting the number of entire cycles observed for a pre-set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HPSDR
The OpenHPSDR (High Performance Software Defined Radio) project dates from 2005 when Phil Covington, Phil Harman, and Bill Tracey combined their separate projects to form the HPSDR group. It is built around a modular concept which encourages experimentation with new techniques and devices (e.g. SDR, Envelope Elimination and Restoration) without the need to replace the entire set of boards. The project has expanded from the original group, and several additional people have been involved in recent HPSDR module designs. The core modules of the project are the Atlas passive backplane, the Ozy interface which provides a USB 2.0 data channel between the HPSDR system and the host PC, and the Mercury and Penelope receiver and exciter boards, which use high speed ADCs and DACs for direct conversion of received or transmitted signals in the DC to 55 MHz frequency range. Mercury has attracted wide interest within the HPSDR community as a general-coverage, high performance, HF re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARRL
The American Radio Relay League (ARRL) is the largest membership association of amateur radio enthusiasts in the United States. ARRL is a non-profit organization, and was co-founded on April 6, 1914, by Hiram Percy Maxim and Clarence D. Tuska of Hartford, Connecticut. The ARRL represents the interests of amateur radio operators before federal regulatory bodies, provides technical advice and assistance to amateur radio enthusiasts, supports a number of educational programs and sponsors emergency communications service throughout the country. The ARRL has approximately 161,000 members. In addition to members in the US, the organization claims over 7,000 members in other countries. The ARRL publishes many books and a monthly membership journal called ''QST''. The ARRL is the primary representative organization of amateur radio operators to the US government. It performs this function by lobbying the US Congress and the Federal Communications Commission. The ARRL is also the internati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TAPR Open Hardware License
The TAPR Open Hardware License (TAPR OPL) is a license used in open-source hardware projects. It was created by Tucson Amateur Packet Radio (TAPR), an international amateur radio organization. Version 1.0 was published on May 25, 2007. Like the GNU General Public License, the OHL is designed to guarantee freedom to share and to create, and forbids anyone who receives rights under the OHL to deny any other licensee those same rights to copy, modify, and distribute documentation, and to make, use and distribute products based on that documentation. Conditions Although the TAPR OHL aims to maintain the philosophy of open-source software, there are obvious differences in physical reality which require some differences in licenses. As a result, the license defines two conditions: Documentation, as in design information; and Products, the physical products created from them. Adoption The TAPR OHL is the license for the materials from the Open Graphics Project as of April 7, 2009. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
